This invention relates to go-carts, especially four wheel go-carts driven by small gasoline engines in the range of eight to fifteen horsepower. Such go-arts commonly are provided in two or more different sizes to accommodate a child or adult driver (or two persons side-by-side).
Conventional go-carts have a relatively stiff and uncomfortable suspension. The broad purpose of the present invention is to provide an improved go-cart having a high strength frame with improved front and rear suspensions.
The go-cart has an elongated main frame with a front end and a rear end. A pair of front wheels are mounted on the front end and a pair of rear wheels are mounted on the rear end, each by their respective suspension means.
The front end suspension comprises a pair of generally horizontal trailing arms mounted on opposite sides of the main frame. The rear end of each trailing arm is pivotally connected to the main frame so that both trailing arms pivot about a common axis that is transverse to the longitudinal axis of the main frame. This permits the forward end of each trailing arm to independently swing in an up and down motion vertical motion.
A linkage mechanism connects the front end of each trailing arm to the main frame. A t-shaped shock tower structure is attached to the forward end of the main frame. A pair of generally horizontal parallel trailing arm rods are connected between the shock tower and each of the front trailing arms. Each pair of trailing arm rods includes an upper rod having an inner end connected by a ball joint to the shock tower and a lower rod connected by a ball joint to the shock tower. The ball joints on the inner ends of the two trailing arm rods are aligned along a generally vertical axis.
The two trailing arm rods have equal lengths and are connected by ball joints to the forward end of their respective trailing arm. The vertical distance between the ball joints connected to the trailing arm is identical to the vertical distance between the ball joints of the inner ends of the rods. This arrangement permits the forward end of each trailing arm to swing up and down constrained by the two parallel trailing arm rods so that the trailing arm moves parallel to the axis of the shock tower.
A wheel is mounted by a clevis and pin means to the forward end of each trailing arm so that the wheel always moves in an up and down motion with respect to the main frame parallel to the shock tower. A pair of shock absorbers connect the upper end of the shock tower to the outer ends of the trailing arms to dampen the up and down motion of the front wheels.
The rear wheels are carried on an axle supported by a pair of swinging arms. The swinging arms are connected to the main frame to pivot about an axis that extends transverse to the longitudinal axis of the main frame.
The main frame supports a gasoline engine which drives a drive sprocket about the same axis as the pivot axis of the swinging arms. A driven sprocket is carried on the rear wheel axle. The two sprockets are connected by a chain in such a manner that as the rear wheels move up and down, the chain moves around the two sprockets with a constant tension. This improves the life of the chain and reduces any tendency of the chain to stretch through use.
The entire frame is formed of a rectangular tubing which provides a much stronger frame structure than conventional go-cart frames.
Specific features of the invention will be apparent from the attached drawings and description of an illustrative embodiment of the invention.